Rocking front wheel mounting for tricycle-type tractor



.1. MoRKosKl May 6, 1952 ROCKING FRONT WHEEL MOUNTING FOR TRICYCLE-TYPE TRACTOR Filed Feb. 26, 1948 Patented May 6, 1952 ROCKING FRONT WHEEL MOUNTING FOR TRICYCLE-TYPE TRACTOR James Morkoski, Canton, Ill., assigner to International Harvester Company, a corporation of New Jersey Appiieation February 2e, me, serial No. 11,25?,V

' This `'invention relates to vehicles and particularly to a tractor of the tricycle or general purpose type.

ATricycle type tractors comprise generally a longitudinally extending body, a transverse rear axle structure at the ends of which are provided rear drive Wheels, and the front end of the body is supported upon a'wheeled unit including a pair of closely spaced wheels mounted on opposite sides 4of a vertically extending steering post. The two front wheels of the tricycle type tractor carry equal weight only when the tractor is traveling on level ground. It has been observed that when a plow, for example a right hand plow, is being drawn behind a tricycle tractor' and the right rear drive wheel of the tractor is traveling in the furrowpreviously'formed by the plot the tractor has a tendencyto` pull'very strongly to the right.` The opposite is true when a left hand .plow is being operated and the left tractor drive wheel is traveling below the level of the ground inithe furrow formed by the plow, in the latter case the tractor being pulled or tending to wander to the left.

f In the conventional type of tricycle tractor if we assume that the right hand tractor drive wheel is traveling below the surface of the ground in a furrow, the left hand wheel of the front dirigible supporting unit will be lifted from the ground and due to the angle assumed by the tractor, all of the weight will be placed upon the right hand wheel of the forward unit. Thus the right hand wheel is subjected to considerable wear because the load is concentrated on that wheel. It has been discovered that this fact is the major contributing factor in the tendency of the tractor to pull to the right, since this will occur when no implement is being operated by the tractor.

` It is the principal object of the present invention to provide a front wheel construction for a tricycle type tractor which will overcome the foregoing disadvantages.

Another object of the present invention is to provide a mounting for the front supporting wheels which will accommodate swinging or pivoting thereof about a horizontal axis extending in the direction of travel of the tractor.

A further object of the invention is to provide a wheel mounting for a vehicle that will accommodate pivoting thereof about a horizontal axis to compensate for the tilting of the vehicle when the wheels on one side or the other are traveling in a furrow below the surface of the ground` A further object of the invention is to provide 1 Claim. l (Cl. 1550-27) wobbling of the wheel unit.

in a tricycle type tractor a -frontwheel'mount-` ing which will accommodatepivoting ofthe front wheels aboutl a horizontal` axis to. compensate'. for slightvariations in ground contour. K

Other objects and advantages ofthe' inveiif tion willfbecome clear from the 'following-dern tailed description when read in conjunction with the accompanying drawings, wherein:

Fig. 1 is an elevation of the dirigible front wheels of a tricycle type tractor showing" the structure vcovered by the present invention.'

Fig. 2 is aview in partial section taken on the line 2'-2 of Fig. 1.

Fig. Sis a frontelevation of a tractor shoW`"" ing the action of the dirigible front Wheels when one of the` tractorwheels:istrttveling` in a furrow below the surfaceofthegrondi l K Referring tothe drawings-it will befnte'd tlat the numeral I0 'designates' Athe"lorigltudmellsjf extending body of a tractorhaving'-a-ltransverse rear axle structure Il and "rear drive'fwheelsf-I2T'4 The front end of the tractonbody has mounted thereupon a generally vertically extending steering post i3 carried thereupon for rotation about a vertical axis. Steering post I3 serves for the mounting of a front supporting wheel unit generally designated by the numeral I4 and comprising a pair of laterally spaced wheels I5.

Front wheels I5 are spaced closely together to provide the tricycle support for the front end of the tractor and converge in a downward direc'- tion. l

The wheels I5 are mounted upon the steering post I3 by means of a supporting structure comprising a triangularly shaped block I6 having stub axle portions I'I extending outwardly and at an angle downwardly from opposite sides thereof, and upon the cuter ends of which the wheels I5 are journaled. The lower end of block I6 is apertured in a direction longitudinally of the tractor to receive a pivot pin I8, the ends of which are received in apertures in the lower depending portions of the arms I9 of a yoke 20 which is axed by welds 2I to the steering post I3. The

f wheel unit I4 is thus mounted in the yoke 20 for lateral swinging movement about the pin I8 as an axis. It will be noted that the pivot pin I8 extends well below the axis of rotation of the wheels E5 upon the stub axles I'I to provide optimum pivoting of the wheels with respect to the tractor.

The upper end of the block I 6 is provided with a widened portion 22 to provide contact of the block It with the arms I9 of the yoke 20 and prevent Stop members 23 are secured by welding to opposite sides of the block I6 to engage the yoke and limit the pivoting of the wheel unit about pin I8. The pin I8 is held in the yoke by means of setscrews 24.

As will be noted particularly well in Fig. 2, the lower portion of the steering post I3 extending below the-tractor body I is bent rearwardly so that the contact point of each of the wheels I is on a vertical line directly below the axis thereof rather than on a vertical line below the axis of rotation of the steering post. This is to facilitate castering of the wheel unit I4 and provide for steering of each.

As pointed out before, the present construction is provided primarily to compensate for the angle assumed by the tractor when one of the tractor wheels is traveling in a furrow below the level of the ground. With previous constructions wherein a rigid front wheel unit was utilized and where the left hand tractor drive wheel, for example,was traveling in a furrow, all of the weight of the front end of the tractor would be placed upon the left hand wheel I5. However, the present construction provides compensation for such tilting of the tractor and, as shown in Fig. 3 with the left hand rear drive wheel traveling in a furrow, the weight of the front end of the tractor is, by virtue of the pivoting of the wheel unit IIIy about its axis upon the pivot pin I8, equally distributed upon the two wheels I5 so that no excessive wear occurs upon either wheel and there is substantially no tendency of the tractor to pull in the direction in which it is leaning.

It is believed that the present invention will be clearly understood from the foregoing description. However, it should be understood that modifications may be made therein withoutdeparting from the spirit of the invention or the scopeA of the appended claim.

What is claimed is:

In a tricycle tractor having a body, laterally spaced rear drive wheels, a generally vertically extending rotatable steering post carried at the forward end of the body, said steering post having a lower bent portion extending rearwardly and downwardly, a pair of castering adjacent downwardly converging front wheels substantially rigidly connected close together and adapted to ,travel upon the surface, and means for mounting said wheels as a unit on the lower bent portion of said steering post rearwardly of the vertical axis thereof so as to facilitate castering of the wheels and to compensate for the tilt of the tractor caused by one of said drive wheels traveling in the furrow, comprising longitudinally extending pivot means carried at the lower end of the steering post and means for mounting said front wheels on said pivot means below the axes of rotation of said wheels to accommodate lateral swinging of the wheels as a unit when the tractor is tilted.

JAMES MORKOSKI.

REFERENCES CITED The following references are of record'in the file of this patent:

UNITED STATES PATENTS 

